var ajaxPool = [];
function ajax(delegate, uri, data, method, encoding) {
	if (!uri) { alert('错误：未指知异步请求URI，操作失败。'); return; }
	if (!data) data = '';
	if (!method) method = 'get';
	if (!encoding) encoding = 'utf-8';

	var http = ajaxPool.pop();
	if (typeof http == 'undefined' || http == null) {
		var flag = 0;
		
		if (window.XMLHttpRequest) {
			http = new XMLHttpRequest();
		} else if (window.ActiveXObject) {
			var progIDs = [ 'Msxml2.XMLHTTP', 'Microsoft.XMLHTTP' ];
	
			for (var i = 0; i < progIDs.length; i++) {
				try {
					http = new ActiveXObject(progIDs[i]);
					break;
				} catch (ex) { }
			}
		} else {
			flag = 1;
		}

		if (flag) {
			var div = document.createElement('div');
			var rnd = hexRnd('FFFFFF', 16);
			div.innerHTML = '<iframe id="ajax_' + rnd + '" style="width:0px;height:0px;"></iframe>';
			document.body.appendChild(div);
			http = document.getElementById('ajax_' + rnd);
			http.onreadystatechange = function() {
				this.status = this.contentWindow.document.body.innerHTML == '' ? 0 : 200;
				this.responseText = this.contentWindow.document.body.innerHTML;
				statechange();
			}
		}
	}
	
	if (http.tagName && http.tagName.toLowerCase() == 'iframe')
		http.src = uri;
	else
	{
		try {
		    http.abort();
			http.open(method, uri, true);
			if (method == 'post')
				http.setRequestHeader('content-type', 'application/x-www-form-urlencoded');
			http.setRequestHeader('content-type', 'text/html;charset=' + encoding);
			http.setRequestHeader('user-agent', 'MSIE 6.0');
			http.onreadystatechange = statechange;
			http.send(data);
		} catch(e) {
			alert('错误：（在准备申请“' + uri + '”资源时）\r\n' + e.message);
			ajaxPool.push(http);
		}
	}

	function hexRnd(hex) {
		return parseInt(Math.random() * parseInt(hex, 16)).toString(16);
	}

	function statechange() {
		if (http.readyState == 4) {
			switch (http.status) {
				case 200:
					if (delegate) delegate(http.responseText, http);
					ajaxPool.push(http);
					break;
				default:
					//if(confirm('错误：（在申请“' + uri + '”资源时）\r\n网络断线或超时。\r\n\r\n1）点击确定重试。'))
					window.defaultStatus = '错误：（在申请“' + uri + '”资源时）\r\n网络断线或超时。\r\n\r\n1）';
					setTimeout(function() {
						window.defaultStatus = '';
						ajax(delegate, uri, data, method, encoding);
					}, 1000);
					break;
			}
		}
	}
}

function trans(delegate, xmlPath, xslPath) {
	var xsl = null;
	var xml = null;
	ajax(function (rt, sender) {
		xsl = sender.responseXML;
		if(xml) delegate(xml.transformNode(xsl));
	}, xslPath);
	ajax(function (rt, sender) {
		xml = sender.responseXML;
		if(xsl) delegate(xml.transformNode(xsl));
	}, xmlPath);
}